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I personally don't think any Edison reproducer should be so stiff that the weight does NOT shift in the runout area and contact the limit loop. In fact, didn't the whole concept of the Duncan stop rely on the bottom weight being loose enough to shift to the limit loop in the runoff area?

I also wondered previously if the angle of the stylus in the runoff area (straining against the limit loop as opposed to centered in it) made a difference. I've tried holding the limit pin in the center in the runoff area, but don't recall any major change. Personally, I don't feel that the "runoff area" test is the be all and end all, except to diagnose pretty major diamond wear/flaws. The reproducer I use most leaves very faint lines in the runoff area (even this is dependent on the particular disc), but if I cannot see change/damage to the actual grooves during play of a relatively pristine record, I'm not concerned with a repro that leaves LIGHT lines in the runoff area.

It might also be interesting to note observations from anyone who has purchased a NOS, never-used diamond or reproducer. After cleaning and making sure the hinge pin and wight block were lubricated and moved freely, I've seen runoff lines even with NOS reproducers.
[EDIT:] Sorry, HMV, missed your post above regarding this.

All these theories are interesting. Some probably have some validity. My observations has been that many original disc if not being exposed to what ever the cause of scoring might be, are in fact still shiny and only might show the slightest of faint lines under good lighting. So long as the stylus is working as it should, the limit pin has no effect on the surface or they would have been marked already 70 years ago. Since once in a while well taken care of records do come along and show no wear to the run off its pretty much a given that originally they stayed that way. Something in the mean time has effected the stylus to cause it to wear or score the record. In most of my cases it was due to fractures or chips which the new stylus are prone too. Older diamonds also were prone to that problem but in my opinion I think the quality of the diamond was such on the originals that they weren't so fragile as the new ones. Steven Medved and Ron H have both studied the stylus that were causing problems and sent me photos of some of the close ups under the microscope. They show damage to the stylus which in turn cause damage to the records. This is why I stated that playing records that had "hazards" of chips, cracks or depressions in them could be the cause of a diamond failure. I was before that all was pointed out to me by Steven, like some who thought that a diamond being the hardest of minerals probably were unaffected by such issues. But that isn't the case.

That isn't to say that the new stylus are good from the start as I have had a number that showed major scratching from the moment they were first lower on a record. I had a long talk with Expert one day and it was their opinion that no diamond under that amount of pressure could run on the surface without leaving marks.. I pointed out to no avail that if that were the case the run off areas we see that are still good would not be possible. It made no difference.

I too wonder at times if the standard steel needle type machines are the way to go as I have many records from the early 20's purchased new in the boxes in the late 50's and to this day show no sign of use. I am sure under a microscope it would be obvious, but not enough to effect the listening so far. The Thing Edison has going for it is the amazing amount of realistic sound that is produced. Some late acoustic recordings by Victor an Columbia and others do have very rich sounds as well, but at a distance I can usually detect a more soild and realist sound from the edison.

Larry

HisMastersVoice wrote:I've also tried placing the stylus on the lead-in area to see if it happens there as well and I have observed that it does not. The limit pin seems to ride in the center at the beginning, so you may be onto something here. Does the weight shift at the end because of increased centrifugal force or something?

I suspect you're correct about the centripetal force, HMV. However, I'm not a physics guy (um, Mr. Bogantz? )
Due to the functioning of the Duncan stop, I'd say the pin is definitely supposed to contact the limit loop in the runoff area.

coyote wrote:

HisMastersVoice wrote:I've also tried placing the stylus on the lead-in area to see if it happens there as well and I have observed that it does not. The limit pin seems to ride in the center at the beginning, so you may be onto something here. Does the weight shift at the end because of increased centrifugal force or something?

I suspect you're correct about the centripetal force, HMV. However, I'm not a physics guy (um, Mr. Bogantz? )
Due to the functioning of the Duncan stop, I'd say the pin is definitely supposed to contact the limit loop in the runoff area.

Coyote, I agree re. that limit pins were supposed to contact the limit loop on the left so that the Duncan connection would be made...or at least they were observed to already be doing so (under forces ably described by Chuck) and the Edison people then thought "Wow, a connection is being made; let's run electricity through it and create a nifty shut-off system for the cash-flush 1919 market."

Of course, as soon as the stylus left the last groove and the limit pin/limit loop connection was made, the Duncan stop was triggered and there would be virtually no scoring in that case. Which leads to another interesting question: was the Duncan stop meant primarily to prevent dead zone scoring--which might have been freaking people out as much in 1919 as it does Brandon, myself and many other DD collectors today?

Ralph

Chuck wrote: Now, combine all of that with what Ralph has
already observed about when the limit pin
rubs against the straight edge of the limit
loop, that creates just enough more friction
to start the scoring...

This all is a great testimony to the fact
that this whole DD system has to be operating
right up on the hairy edge of having so
much weight that it just hardly takes anything
to set it off into destructo territory.

My thought is this: The Edison DD system has
almost got to hold the all-time record for
the absolute heaviest-weighted jewel stylus
playback system ever yet devised by mankind.

To me, the die was cast for it, the handwriting for it was on the wall already
with the "Diamond" series of cylinder
reproducers. Those weights on those things
are heavy, heavy hunks of metal too.
Set one of those down on a black wax amberol
record by mistake, and guess what? (no more
record!)

So, yeah, Blue Amberols were the start of
making something which could stand up to
*extreme* weight. The DDs followed suit.

Hey, you know....??

No wonder when vacuum tube amplifiers were
first devised and much lighter electric
pickups were made....that was considered
real advancement.

We are seeing now first-hand why the brute-force method of having the record groove itself power the diaphragm directly under
the influence of a weight approximately the
same as that of a railroad locomotive, that it might not work real great some of the time.

Again, I find the fact that Edison was able
to come up with a phenolic resin compound
for this application which worked even
a little bit, (much less as a commercially
viable thing), simply a miracle!

After reading about these DD issues and thinking about all that weight, I cringe
every time I consider that diamond point being
set down on those records.

Now, take all of that and add in the whole
business about the inferior grade of repro
DD styli which break down, crack, wear out
and give extremely poor results, I am not
sure I am in any sort of a hurry to get my
first DD machine. I would if I could find
a few NOS genuine Edison DD styli. But I am
not going to even bother messing with those
UK ones....

Chuck

Chuck, I'm no technical wizard nor theorist; I'm a musician and cultural historian. But if one wants to own and play a DD machine, one must of necessity become a technician of sorts as the darned machine demands it. I've quoted you at length above as I think you are RIGHT ON, bro. Yes, the DD system was tottering on the edge of destruction--and then in 1926 Edison went batsh*t crazy and invented the LP system, which involved even more force relative to surface.

But I think that is why so many of us love Edison and his DD system: his combination of stubborn adherence to unconventional (and increasingly antiquated) processes--balanced by his remaining resourcefulness and resources (i.e. a talented, loyal staff).

I've gone as far as my own resources and limited skills of technical analysis will allow. I look forward to sitting back and hearing more experts weigh in on this matter (the ones who've already been mentioned by some of you; PM them and urge these luminaries to give this thread the benefit of their wisdom).

I want to end this statement with a shout-out to our colleague "Edisone." I want to say that ALL of us who respect Edison have more in common than not; I hope no offense was given to you as this topic wends its way. I like using humor, but have to be more careful of it. Also, I know that I can be a bit of a bull in a China shop; I know you weren't a fan of my DD stylus thread (re. "angle of attack"--truth told, I was more wrong on that one than right, I now see in retrospect). Edisone, in many ways the DD system DID work as intended (you and Larry Hollenberg have similar attitudes here--and I have great respect for Larry's perspective too). It is good to start with the Edison manuals and literature--and you are an expert in those. We are united in our desire to preserve and promote interest in that wackiest/most ingenious of phono systems, the Edison DD (OK, second to American Pathé when it comes to wacky).

PLUS, as Larry Hollenberg said, the Edison DD had the sweetest, best sound up to the introduction of the microphone. It IS worth the trouble.

Ralph

Just a thought. If the run offs had been subject to noticeable marking from the start then we wouldn't be complaining today about the stylus leaving the marks on our pristine records.

Larry

Relying on the marks that the DD stylus leaves in the smooth runout area of a DD is probably only good as an approximate indicator of stylus condition. I know that it is possible to witness very little scoring when doing this test with some stylus and record combinations. Yet the same stylus will lightly mark a different record. So the test is imprecise.

It is true that the DD playback mechanics are quite different from those of a steel needle in a record groove. First, the DD record surface of condensite is VERY hard compared with the hardness of a shellac record. Couple that with the extreme hardness of the diamond stylus tip and the VERY HIGH force at the point of contact of the diamond with the condensite and it should be expected that some scoring will result. Since the record material is hard and unyielding, the record deforms very little under the stylus tip and the resultant contact patch at the stylus tip is mere microns in diameter when playing the flat surface of the runout area. This produces probably TONS of force per square inch at the stylus point. This is NOT a problem when playing the record groove because the stylus is shaped and sized to fit quite nicely into the curvature of the groove. This spreads out the tracking force over a MUCH larger area as the stylus tip contacts the groove over a fairly long arc. So the predicting of record groove damage by inspecting the scoring in the flat runout area is misleading at best.

This is not to say that the runout test is useless. Based on my own experiences, I would expect to see anywhere from almost none to a slight marking of the runout area with a good stylus. But if you see excessive scoring with this test, the stylus is probably chipped or imperfectly polished. Anything less than extremely fine and smooth polishing at the contact point will result in scoring of the record. Inspection with a powerful microscope is the only way to judge the stylus condition accurately. If microscopic inspection shows no chips in the stylus, I would imagine that the newly manufactured DD stylus may be insufficiently micro-polished which is resulting in its marking of the flat runouts on DD records. It may be perfectly fine if it were further polished. I would suggest playing some DD records that you don't value highly to micro polish the new stylus before you use it on your valued DDs. You can check for black residue after playing these records to evaluate when the stylus is sufficiently polished.

It has been suggested here that such polishing by record playback would not be effective as the diamond is so hard. That is not true. A diamond stylus tracking at just a few grams will wear noticeably when playing MUCH softer vinyl records after only a few hours of play. This has been confirmed by scanning electron microscopic inspection. I used to do it all the time at RCA Records when I was evaluating record materials for their wear properties. So at the much higher forces involved with DD playback, it should take the playback of only a few DD sides to effectively polish a diamond DD stylus.

larryh wrote:Just a thought. If the run offs had been subject to noticeable marking from the start then we wouldn't be complaining today about the stylus leaving the marks on our pristine records.

Larry

It doesn't necessarily follow that the run offs were subject to noticeable marking from the start.

This is where some pretty esoteric historical research is needed. What was the likelihood back in the day that the limit pin would hit the limit loop in the run off? Was that a product of differing rear hinges in differing reproducers (note my comment somewhere above that I have one that has two securing screws while another has three). Also, might not 90 years of aging, adjustments, and replacements have loosened some of these reproducers so that they would shift in the run off in ways not originally intended?

Here's a question for you, Larry. One of my reproducers is one of the Duncan stop ones; it has the hole in the back for the electrode. THAT was one model, if ever there was one, that was MEANT to allow the limit pin to hit the limit loop in the run off as that was necessary for the Duncan stop. Guess what? In the one I have, when it proceeds into the run-off, the limit pin remains centered! Now, see: here's another example of an Edison component NOT acting the way it should. Why? Because we've had 90 years of people making adjustments to these components. So, plenty of DD reproducers are acting today in ways they did not 90 years ago; ones that originally would have allowed "drift" and the Duncan connection no longer do (as is the case with mine)--whereas others that originally did not allow that drift now DO.

I can tell, my friend (and you know I genuinely regard you as such), that you still want to blame the styli. In your household you have a bunch of DD styli you've sent to bed without supper because you assume they've been bad--based on run-off scoring alone. They're crying their little eyes out--sobbing into their pillows. At least send them out to be checked under a microscope.

There are a few offshoots of this DD stylus
pin problem thread.

Actually, this thread could very easily expand
out into one which would talk about DD stylus
problems in general.

From reading of all the difficulties encountered with this DD system in general,
I am now, personally, settling in and focusing
on the original Edison DD styli, vs the
Expert ones.

One thing that has dawned on me is about
how the original diamonds were mounted in the
stylus bar. I read somewhere that somehow
the opening in the bar that holds the diamond
in the bar was shrunk-fit somehow, so that the
diamond ends up being subjected to a compression force of many thousands of pounds.

Has anyone else heard of that?

I am wondering if maybe that has something to
do with why the Edison originals stand up so
much better than the Expert reproductions?

Sorry if this goes too much off-topic.
If it does, I'll start another thread for it.
Basically it all boils down to I am not very
interested in having a DD machine unless I
can find a few good-shape, decent Edison
original DD styli.

Chuck

pughphonos wrote:One of my reproducers is one of the Duncan stop ones; it has the hole in the back for the electrode. THAT was one model, if ever there was one, that was MEANT to allow the limit pin to hit the limit loop in the run off as that was necessary for the Duncan stop. Guess what? In the one I have, when it proceeds into the run-off, the limit pin remains centered!

You may need to disassemble and clean/polish/oil the pivot parts, the weight should be able to move freely.